SpringBoot浅析缓存机制之Ehcache 2.x应用

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
  <groupId>net.sf.ehcache</groupId>
  <artifactId>ehcache</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-test</artifactId>
  <scope>test</scope>
</dependency>

<ehcache>
    <diskStore path="java.io.tmpdir/cache"/>
    <defaultCache
            maxElementsInMemory="10000"
            eternal="false"
            timeToIdleSeconds="120"
            timeToLiveSeconds="120"
            overflowToDisk="false"
            diskPersistent="false"
            diskExpiryThreadIntervalSeconds="120"
    />
    <!--
        name：缓存名称
        maxElementsInMemory：缓存最大个数
        eternal：缓存对象是否永久有效。一旦设置了永久有效，timeout将不起作用
        timeToIdleSeconds：缓存对象在失效前允许闲置时间（秒），当eternal为false时生效
        timeToLiveSeconds：缓存对象在失效前允许存活的时间（秒），当eternal为false时生效
        overflowToDisk：当内存中的对象数量达到maxElementsInMemory时， Ehcache 是否将对象写到磁盘中
        diskExpiryThreadIntervalSeconds：磁盘失效线程运行时间间隔
    -->
    <cache name="book_cache"
           maxElementsInMemory="10000"
           eternal="true"
           timeToIdleSeconds="120"
           timeToLiveSeconds="120"
           overflowToDisk="true"
           diskPersistent="true"
           diskExpiryThreadIntervalSeconds="600"/>
</ehcache>

@SpringBootApplication
@EnableCaching
public class CacheApplication {
    public static void main(String[] args) {
        SpringApplication.run(CacheApplication.class, args);
    }
}

public class Book implements Serializable {
    private Integer id;
    private String name;
    private String author;
    @Override
    public String toString() {
        return "Book{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", author='" + author + '\'' +
                '}';
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAuthor() {
        return author;
    }
    public void setAuthor(String author) {
        this.author = author;
    }
}

@Repository
@CacheConfig(cacheNames = "book_cache")
public class BookDao {
    @Cacheable
    public Book getBookById(Integer id) {
        System.out.println("getBookById");
        Book book = new Book();
        book.setId(id);
        book.setName("三国演义");
        book.setAuthor("罗贯中");
        return book;
    }
    @CachePut(key = "#book.id")
    public Book updateBookById(Book book) {
        System.out.println("updateBookById");
        book.setName("三国演义2");
        return book;
    }
    @CacheEvict(key = "#id")
    public void deleteBookById(Integer id) {
        System.out.println("deleteBookById");
    }
}

@Component
public class MyKeyGenerator implements KeyGenerator {
    @Override
    public Object generate(Object target, Method method, Object... params) {
        return Arrays.toString(params);
    }
}

@Service
@CacheConfig(cacheNames = "book_cache")
public class BookDao {
    @Autowired
    MyKeyGenerator myKeyGenerator;
    @Cacheable(keyGenerator = "myKeyGenerator")
    public Book getBookById(Integer id) {
        System.out.println("getBookById");
        Book book = new Book();
        book.setId(id);
        book.setName("三国演义");
        book.setAuthor("罗贯中");
        return book;
    }
    @CachePut(key = "#book.id")
    public Book updateBookById(Book book) {
        System.out.println("updateBookById");
        book.setName("三国演义2");
        return book;
    }
    @CacheEvict(key = "#id")
    public void deleteBookById(Integer id) {
        System.out.println("deleteBookById");
    }
}

@RunWith(SpringRunner.class)
@SpringBootTest
public class CacheApplicationTests {
    @Autowired
    BookDao bookDao;
    @Test
    public void contextLoads() {
        bookDao.deleteBookById(1);
        bookDao.getBookById(1);
        bookDao.getBookById(1);
        bookDao.deleteBookById(1);
        Book b3 = bookDao.getBookById(1);
        System.out.println("b3:"+b3);
        Book b = new Book();
        b.setName("三国演义");
        b.setAuthor("罗贯中");
        b.setId(1);
        bookDao.updateBookById(b);
        Book b4 = bookDao.getBookById(1);
        System.out.println("b4:"+b4);
    }
}